On 15.03.24 11:55, Ryan Roberts wrote:
On 15/03/2024 10:35, David Hildenbrand wrote:- if (!pageout && pte_young(ptent)) { - ptent = ptep_get_and_clear_full(mm, addr, pte, - tlb->fullmm); - ptent = pte_mkold(ptent); - set_pte_at(mm, addr, pte, ptent); - tlb_remove_tlb_entry(tlb, pte, addr); + if (!pageout) { + for (; nr != 0; nr--, pte++, addr += PAGE_SIZE) { + if (ptep_test_and_clear_young(vma, addr, pte)) + tlb_remove_tlb_entry(tlb, pte, addr); + } }The following might turn out a bit nicer: Make folio_pte_batch() collect "any_young", then doing something like we do with "any_writable" in the fork() case: ... nr = folio_pte_batch(folio, addr, pte, ptent, max_nr, fpb_flags, NULL, any_young); if (any_young) pte_mkyoung(ptent) ... if (!pageout && pte_young(ptent)) { mkold_full_ptes(mm, addr, pte, nr, tlb->fullmm); tlb_remove_tlb_entries(tlb, pte, nr, addr); }I thought about that but decided that it would be better to only TLBI the actual entries that were young. Although looking at tlb_remove_tlb_entry() I see that it just maintains a range between the lowest and highest address, so this won't actually make any difference.
Yes, tlb_remove_tlb_entries() looks scarier than it actually is :) -- Cheers, David / dhildenb
